Category Archives: Disaster Risk Reduction

【Disaster Research】When Nature Meets Human Error: Lessons from History’s Deadliest Volcanic Mudflow 40 Years Ago

Growing up, many of us were taught that natural disasters are inevitable acts of nature beyond human control. This perspective changed dramatically for me when I started working at a research institute. My senior researcher emphatically told me, “The natural disaster is not natural.” This profound statement transformed my approach to disaster research, helping me understand that human decisions often determine whether natural hazards become catastrophic disasters.

The Forgotten Tragedy of Armero

On November 13, 1985, the Nevado del Ruiz volcano in Colombia erupted after 69 years of dormancy. The eruption triggered massive mudflows (lahars) that rushed down the volcano’s slopes, burying the town of Armero and claiming over 23,000 lives. This catastrophe stands as Colombia’s worst natural hazard-induced disaster and the deadliest lahar ever recorded.

What makes this tragedy particularly heartbreaking is its preventability. Scientists had observed warning signs for months, with seismic activity beginning as early as November 1984. By March 1985, a UN seismologist had observed a 150-meter vapor column erupting from the mountain and concluded that a major eruption was likely.

Despite these warnings, effective action to protect the vulnerable population never materialized. The devastation of Armero wasn’t simply the result of volcanic activity but the culmination of multiple human failures in risk communication, historical memory, and emergency response.

When Warning Systems Fail: Communication Breakdown

The Armero disaster epitomizes what disaster researchers call “cascading failures” in warning systems. Scientists had created hazard maps showing the potential danger to Armero in October 1985, just weeks before the eruption. However, these maps suffered from critical design flaws that rendered them ineffective.

One version lacked a clear legend to interpret the colored zones, making it incomprehensible to the general public. Devastatingly, Armero was placed within a green zone on some maps, which many residents misinterpreted as indicating safety rather than danger. According to reports, many survivors later recounted they had never even heard of the hazard maps before the eruption, despite their publication in several major newspapers.

As a disaster researcher, I’ve seen this pattern repeatedly: scientific knowledge fails to translate into public understanding and action. When I conducted fieldwork in flood-prone regions in Thailand, I discovered a similar disconnect between technical risk assessments and public perception. Effective disaster mitigation requires not just accurate information but information that is accessible and actionable for those at risk.

The Cultural Blindspots of Risk Perception

The tragedy of Armero illustrates how cultural and historical factors shape how communities perceive risk. Despite previous eruptions destroying the town in 1595 and 1845, causing approximately 636 and 1,000 deaths respectively, collective memory of these disasters had seemingly faded as the town was rebuilt in the same location.

In the hours before the disaster, when ash began falling around 3:00 PM, local leaders, including the town priest, reportedly advised people to “stay calm” and remain indoors. Some residents recall a priest encouraging them to “enjoy this beautiful show” of ashfall, suggesting it was harmless. These reassurances from trusted community figures likely discouraged self-evacuation that might have saved lives.

My research in disaster-prone communities has consistently shown that risk perception is heavily influenced by cultural factors, including trust in authority figures and historical experience with hazards. In Japan, for instance, the tsunami markers that indicate historic high-water levels serve as constant physical reminders of past disasters, helping to maintain community awareness across generations.

Systemic Failures and Institutional Response

The Armero tragedy wasn’t just a failure of risk communication or cultural blind spots—it revealed systemic weaknesses in disaster governance. Colombia was grappling with significant political instability due to years of civil war, potentially diverting governmental resources from disaster preparedness. Just a week before the eruption, the government was heavily focused on a guerrilla siege at the Palace of Justice in Bogotá.

Reports suggest there was reluctance on the part of the government to bear the potential economic and political repercussions of ordering an evacuation that might have proven unnecessary. This hesitation proved fatal when communication systems failed on the night of the eruption due to a severe storm, preventing warnings from reaching residents even after the lahars were already descending toward the town.

In my research examining large-scale flood disasters, I’ve found that effective disaster governance requires robust institutions that prioritize public safety over short-term economic or political considerations. My 2021 comparative analysis of major flood events demonstrated that preemptive protective actions consistently save more lives than reactive emergency responses, even when accounting for false alarms.

Learning from Tragedy: The Path Forward

The Armero disaster, while devastating, catalyzed significant advancements in volcano monitoring and disaster risk reduction globally. Colombia established specialized disaster management agencies with greater emphasis on proactive preparedness. The

Colombian Geological Service expanded from limited capacity to a network of 600 stations monitoring 23 active volcanoes.

The contrast with the 1991 eruption of Mount Pinatubo in the Philippines demonstrates the impact of these lessons. There, timely forecasts and effective evacuation procedures saved thousands of lives. The memory of Armero remains a powerful reminder of the consequences of inadequate disaster preparedness.

As I’ve emphasized in my own research on disaster resilience in industrial complex areas, building sustainable communities requires integrating technical knowledge with social systems. My work developing social vulnerability indices demonstrates that effective disaster risk reduction must address both physical hazards and social vulnerabilities.

Remember, disasters may be triggered by natural events, but their impact is determined by human decisions. By learning from tragedies like Armero, we can create more resilient communities prepared to face future challenges.

【Disaster Research】ADRC: Kobe’s Legacy in Asian Disaster Risk Reduction

From Tragedy to Leadership: The Birth of ADRC

The Asian Disaster Reduction Center (ADRC) was established in 1998 following the devastating Great Hanshin-Awaji Earthquake (commonly known as the Kobe Earthquake) that struck Japan in 1995. This catastrophic event became a catalyst for change, transforming how Japan—and later Asia—approached disaster management and resilience.

Kobe’s Remarkable Recovery Journey

Kobe’s recovery story stands as a powerful testament to resilience and strategic rebuilding. Within just 9 years after the earthquake, Kobe’s population returned to pre-disaster levels—an extraordinary achievement considering the scale of destruction. This recovery wasn’t merely about rebuilding structures but reimagining the city’s future role.

HAT Kobe: A Hub for Disaster Reduction Excellence

Today, Kobe has reinvented itself as a global center for disaster reduction policies and activities. The area known as HAT Kobe hosts numerous disaster-related organizations, including ADRC. The name “HAT” carries dual significance:

  • It stands for “Happy and Active Town”
  • In Japanese, “hatto” (ハッと) means “surprised” or “sudden realization”

This wordplay perfectly captures Kobe’s transformation from a disaster-struck city to a knowledge hub that helps others prepare for and respond to unexpected disasters.

Learning From Kobe: A Model for Disaster Recovery

Kobe’s recovery process offers valuable lessons for communities worldwide facing similar challenges. The city demonstrates how effective post-disaster planning can transform tragedy into opportunity, creating not just infrastructure but institutional knowledge that benefits others.

ADRC’s Mission Across Asia

ADRC plays a vital role in sharing disaster reduction expertise with its member countries throughout Asia. The organization:

  • Contributes to disaster reduction policy development
  • Supports member countries in implementing effective disaster management systems
  • Facilitates knowledge sharing through detailed country reports
  • Monitors and reports on ongoing disaster situations

Resources for Disaster Management Professionals

ADRC maintains comprehensive resources that disaster management professionals can access:

These resources provide valuable insights into regional disaster management systems, country-specific approaches, and up-to-date information on current disaster situations across Asia.

Building Regional Resilience Together

Through organizations like ADRC and the example set by Kobe, Asian countries are developing stronger collaborative approaches to disaster risk reduction. By learning from past experiences and sharing knowledge, communities across the region are better prepared to face future challenges with resilience and determination.

【Disaster Research】Thailand Natural Disaster Risk Assessment: A Comprehensive Analysis (Revised)

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Understanding Disaster Risk Profiles in Thailand

As highlighted in the Bangkok Post article, “More must be done to fight climate change“, Thailand faces significant challenges from various natural disasters. This analysis presents a national risk assessment mapping to help identify priority areas for disaster management.

Historical Disaster Impact Analysis

Table 1  Disaster data in Thailand

em-dat_thailand
The EM-DAT database analysis covers disasters from 1900 to 2014. Notably, the most severe impacts—measuring deaths, affected populations, and economic damage—have occurred primarily since the 1970s. Two catastrophic events stand out in Thailand’s disaster history:

These events have dramatically shaped Thailand’s approach to disaster risk management.

Risk Assessment Mapping Framework

riskmapping_thailand
Figure 1 National Risk Assessment Mapping in Thailand

The above visualization presents Thailand’s risk assessment map created using EM-DAT data spanning 1900-2014. This frequency-impact analysis by damage type offers a straightforward yet comprehensive overview of Thailand’s disaster risk landscape.

Risk Evaluation Matrices

To properly contextualize these risks, we employ two complementary evaluation matrices:

riskoption1
Figure 2 Risk matrix options (1)

riskoption2
Figure 3 Risk matrix options (2)

Key Findings and Priorities

The risk assessment mapping (Figure 1) clearly identifies flooding as Thailand’s most critical disaster risk requiring immediate attention and resources. According to the evaluation matrices shown in Figures 2 and 3, flood events necessitate:

  • Extensive management systems
  • Comprehensive monitoring networks
  • Immediate action planning and implementation

This preliminary analysis serves as a foundation for more detailed research. A report for the conference (Conference: 13th International Conference on Thai Studies) has published a more comprehensive examination of these findings.

Additional Resources

For more information on disaster risk reduction in Southeast Asia, visit the natural hazards research journal (open access) .

Day_64 : 1985 Nevado del Ruiz Volcano Eruption

One of the most significant volcanic disasters we must know about is the 1985 Nevado del Ruiz volcano eruption. Approx.23000 citizens in Armero city were dead. The cultural aspects were embedded in this disaster. The disaster was predicted. The hazard maps indicate that the city will be affected by a volcanic eruption and lahars. Both priest and mayor told the citizens to stay in the same place because they were afraid of panic before the time, but did not tell them to evacuate. That made tragedy. The people in the city tended to follow both persons because of the culture, which is a religious and vertically structured society. There were also other factors*.

 

*https://en.wikipedia.org/wiki/Nevado_del_Ruiz#Eruption_and_lahars

 

Day_209 : Snow Disasters: When Winter Wonderland Turns into a Nightmare

Winter’s beauty can turn dangerous with heavy snow, blizzards, and ice storms. These snow disasters cause power outages, transportation chaos, and property damage. But what causes them, and how can we prepare?

The Science of Snowstorms

Snow disasters happen when cold temperatures, precipitation, and wind combine. Think of heavy snowfall, icy roads, and massive snowdrifts. Climate change is making things worse with more intense snow and hazardous ice.

The Impact

Snow disasters disrupt transportation, causing accidents and delays. Power lines snap under the weight of snow, leading to blackouts. Buildings can even collapse, and ice dams cause leaks and damage.

Fighting Back: Snow Removal and Prevention

Traditional methods like shoveling and plowing are still essential. But we now have snowblowers, snowmelt systems, and de-icing techniques. Advanced weather prediction helps us prepare, and GPS-guided snowplows clear roads faster.

Be Prepared!

Even with the best technology, snowstorms can still hit hard. Have an emergency kit with food, water, blankets, and a first aid kit. Plan for transportation and communication in case of an emergency.

Stay safe and warm this winter!

# Image Source: Unsplash‍

 

Day_207 : Lessons from Hurricane Katrina: A Retrospective Analysis and Future Implications for Disaster Risk Reduction

 

The picture was taken in Mississippi on December 3, 2005.

Nearly two decades have passed since Hurricane Katrina devastated the Gulf Coast, particularly New Orleans, in 2005. As we reflect on this catastrophic event, it’s crucial to reassess our understanding of the disaster, its impacts, and the lessons learned for future disaster risk reduction efforts. This updated analysis incorporates new research, recent case studies, and current best practices in disaster management to provide a comprehensive view of Hurricane Katrina’s long-lasting effects and implications for disaster preparedness.

Revisiting the Data: The Importance of Pre-Disaster Information

One of the most valuable resources for understanding the pre-Katrina landscape was the Greater New Orleans Community Data Center (GNOCDC) website. This data repository provided detailed demographic and socioeconomic information at the parish and ward levels, offering crucial insights into the social fabric of affected areas.

Key Findings from Pre-Katrina Data

  1. Vehicle Ownership: Data from GNOCDC revealed significant disparities in vehicle ownership across New Orleans neighborhoods. For instance, the Lower 9th Ward, one of the most severely affected areas, had a low rate of vehicle ownership. This factor critically impaired residents’ ability to evacuate independently, necessitating government assistance for evacuation.
  2. Socioeconomic Disparities: Analysis of household incomes, education levels, and employment rates across different wards highlighted pre-existing vulnerabilities that exacerbated the disaster’s impact.
  3. Housing Quality: Information on housing stock age and quality provided insights into structural vulnerabilities that contributed to the extent of physical damage.

The Victimization Process: A Multi-Stage Analysis

Understanding the disaster’s impact requires examining multiple stages of the event and its aftermath. Building on the original five-stage model (Pre-disaster, Direct Damage, Social Disorder, Life Environment, and Reconstruction and Recovery), recent research has emphasized the interconnectedness of these stages and their long-term implications.

Updated Insights on Disaster Stages

  1. Pre-disaster Stage:
    • New research highlights the critical role of community-based preparedness programs in enhancing resilience.
    • Studies show that areas with strong social networks and community engagement had better evacuation rates and post-disaster recovery.
  2. Direct Damage Stage:
    • Advanced modeling techniques have improved our understanding of infrastructure vulnerabilities, particularly in flood-prone areas.
    • Recent case studies from hurricanes like Harvey (2017) and Ida (2021) provide comparative data on immediate impact patterns.
  3. Social Disorder Stage:
    • Long-term studies have revealed the persistent psychological impacts of displacement and community disruption.
    • New frameworks for maintaining social order during disasters emphasize the importance of clear communication and community leadership.
  4. Life Environment Stage:
    • Research on environmental health impacts has expanded, including studies on mold exposure and water contamination.
    • The concept of “build back better” has gained traction, influencing reconstruction efforts to enhance resilience.
  5. Reconstruction and Recovery Stage:
    • Long-term studies show uneven recovery patterns, with some neighborhoods thriving while others continue to struggle.
    • The role of federal, state, and local policies in shaping recovery outcomes has been extensively analyzed, offering lessons for future disaster recovery planning.

Emerging Trends in Disaster Risk Reduction

Since Hurricane Katrina, several key trends have emerged in the field of Disaster Risk Reduction:

  1. Climate Change Adaptation: There’s an increased focus on integrating climate change projections into disaster preparedness and urban planning.
  2. Community-Based Disaster Risk Management: Emphasizing local knowledge and community participation in disaster planning and response.
  3. Technological Advancements: Utilization of GIS, remote sensing, and AI for improved risk assessment and early warning systems.
  4. Social Vulnerability Mapping: More sophisticated tools for identifying and addressing vulnerabilities based on socioeconomic factors.
  5. Nature-Based Solutions: Growing emphasis on using natural ecosystems to mitigate disaster risks, such as wetland restoration for flood control.

Actionable Recommendations

Based on lessons learned from Katrina and subsequent disasters, here are key recommendations for enhancing disaster resilience:

  1. Invest in Inclusive Preparedness: Ensure evacuation plans and resources are accessible to all community members, especially those with limited mobility or resources.
  2. Strengthen Infrastructure Resilience: Implement stricter building codes and invest in critical infrastructure upgrades, particularly in vulnerable areas.
  3. Enhance Early Warning Systems: Develop multi-channel, culturally appropriate warning systems that reach all segments of the population.
  4. Foster Community Cohesion: Support programs that build social capital and community networks, which are crucial for both evacuation and recovery.
  5. Integrate Social Vulnerability in Planning: Use social vulnerability indices to inform resource allocation and targeted support in disaster planning and response.
  6. Promote Sustainable Recovery: Implement recovery strategies that not only rebuild but also address pre-existing social and environmental issues.
  7. Continuous Learning and Adaptation: Establish mechanisms for ongoing assessment and incorporation of lessons learned from each disaster event.

The tragedy of Hurricane Katrina continues to offer valuable lessons for disaster risk reduction. By combining data-driven analysis with a nuanced understanding of social and environmental factors, we can work towards creating more resilient communities. As we face increasing challenges from climate change and urban growth, the insights gained from studying Katrina’s impact remain crucial for shaping effective disaster management strategies worldwide.

Hurricane Katrina Disaster Research conducted by NIED（in Japanese）

A comparative analysis of large-scale flood disasters

Day_196 : The Matsushiro Earthquake Center

The following is a reprint of a column I once wrote:

The Matsushiro Earthquake Center, nestled in the historic town of Matsushiro within Nagano Prefecture, represents a pivotal chapter in Japan’s approach to seismic research and disaster mitigation. Established in February 1967 under the auspices of the Japan Meteorological Agency’s Seismological Observatory, this institution was born out of a critical period marked by intense seismic activity. Between August 3, 1965, and April 17, 1966, the region experienced a staggering 6,780 seismic events, ranging from imperceptible tremors to significant quakes measuring intensity 5 and 4 on the Japanese scale. This unprecedented series of earthquakes not only posed a major societal challenge but also catalyzed the center’s founding.

The initiative to establish the center was strongly influenced by the then-mayor of Matsushiro, Nakamura, who famously prioritized the pursuit of knowledge and research over material wealth. This sentiment laid the groundwork for what would become a crucial site for earthquake prediction and disaster preparedness efforts, situated on the historical grounds of the Imperial Headquarters.

Drawing from my experience at the Natural Disaster Information Office and in collaboration with the Precise Earthquake Observation Office of the Japan Meteorological Agency (now known as the Matsushiro Earthquake Observatory), I have had the unique opportunity to organize and delve into discussions from that era. Despite being born after the seismic events in Matsushiro, I find the archival records fascinating. They not only recount the collective efforts of Matsushiro’s residents to forge a disaster-resilient community in the aftermath of the earthquake but also highlight the comprehensive nature of the research conducted.

The inquiries extended beyond seismic analysis, encompassing a holistic examination of the earthquake’s impact on the community. Noteworthy is the health survey conducted on students from a local school, in collaboration with the Matsushiro Health Center and hospital, to assess the psychological and physical effects of the seismic swarms. Moreover, the scope of investigation included studies on earthquake-induced landslides and the repercussions on water infrastructure, showcasing the multifaceted response from various experts and frontline workers of the time.

This rich tapestry of collective memory and scientific inquiry underscores the enduring spirit of Matsushiro—a community united in its commitment to disaster resilience, informed by the lessons of its past.

Ref.

http://researchmap.jp/read0139271/%E7%A0%94%E7%A9%B6%E3%83%96%E3%83%AD%E3%82%B0/

Day_115 : Disaster Technology Websites

I want to introduce you to two disaster technology websites: DRH Asia-Disaster Reduction Hyperbase and Global DRR Technology.

  • The websites below are unavailable today (2024.12.14 confirmed); however, we can still learn the concept and idea as a significant theme.

1) DRH Asia
This site provides qualified information about DRR technology. Its content is easy to grasp, making it possible to transfer DRR technology. The content comes from many Asian countries and has been reviewed by experts. The challenge is the limited number of contents.

The following is an example of the contents.
Earthquake Early Warning and its Application to Mitigate Human and Social Damages (Figure 1)

drh
Figure 1

We can understand the quality and availability of the content.

2) Global DRR Technology
This site focuses on an online Community of Practice(CoP) in Disaster Risk Reduction(DRR). Although the content is limited, the site can be easily accessed. The case study site is incredibly visually appealing.

The site below is an example of a case study site. (Figure 2)

global-drr-tech
Figure 2

 

Day_157: Disaster Warning (1)

I will update a column of the NIED e-mail magazine I wrote long ago because the content does not fade with time. (I will do this step by step in Japanese and English.) I will also add comments to update the situation.

Sorry, I am now revising this post because of the translation difficulties. This post will be revised again. Thank you.

Published May 6, 2010
NIED-DIL e-mail magazine: Disaster Warning (1)

■ Disaster Warning (1) ■

In February 2008, a survey provided an opportunity to visit Hawaii’s Pacific Tsunami Warning Center (PTWC). In a study, I interviewed the director of the PTWC, and the first thing that caught my attention was the role of the media. The director told me that a public tsunami evacuation alert was required three hours before the event, which was too time-sensitive, but the press was an advantage to do this. However, there were various restrictions for the government organization, such as warnings in an international framework. I remembered the Chilean Navy’s disaster response to the damage caused by the earthquake and tsunami in Chile in February this year.

Next, I was interested in science, technology, and data, which are the basis of alarm decisions. I think regular (flood, etc.) warnings will be judged based on current and past data, but especially for tsunami warnings, there were errors in the original earthquake and the tide gauge data. To judge, we should know that 99.99 percent of the errors could be caused by error. The fact that past data is not very useful because the devices to figure out the data are changing daily, making it difficult to rely on it.

From these facts, it was generally noticed that the disaster warning was based on the combination of the progress of science and technology and the competence of the person in charge. The actual warning also relies on the institution belonging to it. For example, variables such as the recipient of the alert, the psychology of the local people, the social situation, and various systems also needed to be added.

Issued May 6, 2010 No. 4

Day_199 : Early Signs of Geological Changes Before Landslides

Before significant landslides occur, various clear natural changes are often observed. Notable incidents include the 1963 Vajont Dam landslide in Italy and the 2006 Leyte Island landslide in the Philippines.

On the evening of October 9, 1963, a massive landslide took place near the Vajont Dam in the Alps of northern Italy. The dam, standing at 262 meters, was completed just three years prior. The landslide dislodged approximately 260 million cubic meters of earth, thrusting up the waters of the dam’s lake. The displaced water surged over the dam, rising more than 100 meters before rushing down into the valley below, resulting in approximately 2,000 fatalities. The geological layers in the area were unstable, compounded by the increased water levels from the dam. A minor landslide had previously occurred in 1960, and the landslide’s progress accelerated to several tens of centimeters per day just before the disaster. Despite ongoing monitoring, the catastrophic damage could not be prevented.

Day_140 : Natural Disasters in Europe (2) Vajont Dam Collapse

 

On February 17, 2006, a mountain 800 meters tall on the Philippine island of Leyte succumbed to a vast landslide, displacing around 20 million cubic meters of soil and claiming 1,144 lives. Before the collapse, cracks had appeared on the mountain’s ridge, and rainfall had begun to seep into the ground.

Identifying these early signs of geological change is crucial. By monitoring their progression and predicting potential danger zones, we can enhance our preparedness and safeguard our lives against such devastating natural disasters.

Contents (in Japanese)
Source: URL:https://dil.bosai.go.jp/workshop/2006workshop/gakusyukai21.html

 

What causes a landslide?